How to write this equation in Jitter?

This is an equation for a pendulums frequency – but how would I write this as an equation in Jitter? I am uploading as a .png as I can't replicate the correct formatting on my keyboard. I am no great maths head – hence my question. I have made an attempt but am doing something slightly wrong. If someone could show me it written properly with $f1 as frequency, $f2 as phase, $f3 as Amplitude, $f4 as damping and $f5 for time. These $ variables will be fed by number boxes. Or maybe someone else knows a better way than my suggested rantings??